1. Field of the Invention
The present invention relates to a hydrogen storage alloy electrode and a method for manufacturing it.
2. Description of the Related Art
A paste for a hydrogen storage alloy, used for manufacturing a hydrogen storage alloy electrode for a negative electrode of a nickel-hydrogen secondary battery, is formed by mixing a hydrogen storage alloy powder with various polymer materials, including a conductive powder material, a binding material or a thickening material, with water and by kneading the mixture.
Binding materials are polymer materials for mainly increasing bonding strength between hydrogen storage alloy particles or between hydrogen storage alloy particles and a metallic plate used as a current collector. Further, the thickening materials are polymer materials that increase the viscosity of the paste to ensure an adhesive thickness. In Japanese Unexamined Patent Application No. 4-284354, it is shown to employ more than two materials selected from styrene-butadiene base latex (SBR), fluorine resin (PTFE) and a hydrophilic resin (methyl cellulose) for a paste of hydrogen storage alloy powder and, in Japanese Unexamined Patent Application No. 7-45278, to employ SBR and methyl cellulose for a paste of hydrogen storage alloy powder.